The Design And Implementation Of Network Softswitch System

With development and becoming mature of NGN, the technology of softswitch as core element in NGN is more and more catching people's attention. People define softswitch as one of core elements in next general packet switching network. It is independent of transmit network, and mainly has some functions such as call controlling,assigning resource,protocol process,route,authentication and so on. Meanwhile, it implements all of functions that are only implemented in circuit based network. Besides these functions,the softswitch system supplies user all kinds of APIs. It makes network not only for communication but also for more application services. Softswitch is a software-based switching platform, which is opposed to traditional hardware-based switching center technology. This paper designs and implements the basic function of softswitch and some important expanding functions。The main contents of this paper as the follows: 1) This paper analyzes the technology of VOIP and softswitch and the future of them 2) This paper designs and implements the basic function of network softswitch by research of the technology of softswitch 3) This paper designs and implements the protocol gateway between H.323 and SIP by comparing two protocols 4) This paper designs and implements Voicemail system and voice conference system by API of softswitch The network softswitch that is implemented in this paper is designed for small and middle VOIP application with maximum flexibility, and can perform function of traditional TDM telephone switch and more application services for conforming to the requirements of users .The softswitch system works with several VOIP protocols such as SIP protocol,H.323 protocol and so on, and performs communication and translation between two protocols. It connects with several VOIP networks mainly and is very compatible with VOIP equipments and resource in existence. The network softswitch system supports lots of codecs such as G.711 A-Law ,G.711 μ-Law,G.723,GSM and so on, and can meet the requirement of different network bandwidth and quality of communication.